Today's automobile dashboards represent complex composite molded articles to which this invention is especially applicable, although not limited. Automobile dashboards typically include an outer plastisol skin (plasticized vinyl), intermediate foam layer and inner rigid or semi-rigid plastic support insert. One process for producing such articles includes providing a mold cavity having the outer configuration of the dashboard, laying the plastisol outer skin in the mold cavity so that it will conform thereto, pouring a layer of liquid polyurethane foam onto the skin in the mold and then placing the plastic insert into position in the mold cavity above the liquid polyurethane foam. In this process, the plastic insert is carried on the mold lid which is swung closed over the mold cavity. Once the mold is closed, the liquid polyurethane is caused to foam in the space between the outer skin and inner plastic insert and form the composite dashboard described.
In the manufacture of dashboards having a so-called instrument cluster, there is provided a cluster enclosure having vertically oriented cluster enclosure members projecting sharply from the main body of the dashboard and which have been found to exhibit too much flexibility in a direction transverse to the vertical axis. This lack of stiffness in the vertically-oriented cluster members is attributable to the impracticability or inability to extend the portions of the rigid or semi-rigid plastic support insert into the mold cavity areas forming the vertical cluster enclosure members to provide stiffness. That is, as a result of the projecting angles of the enclosure member cavities relative to the plane of the mold cavity and as a result of the requirement that the plastic insert be loaded into the mold cavity on the mold lid, the portions of the mold cavity defining the vertical cluster enclosure members are not accessible to extensions that might otherwise be provided on the plastic insert for stiffening and are considered die locked from this standpoint.
A means for increasing the stiffness of cluster enclosure members on such automobile dashboards compatible with existing manufacturing methods is thus needed.
A resilient composite urethane structure is disclosed in the Knox U.S. Pat. No. 3,153,853. The patented structure includes an elastomeric solid non-cellular non-planar polyurethane reinforcement to increase load-bearing characteristics.
British patent specification No. 720,549 describes a method for making a molded sponge or cellular rubber article wherein a film of unvulcanized rubber is bonded to a metal insert prior to molding and during molding the rubber introduced into the mold is expanded and vulcanized and unites with and produces vulcanization of the film to enhance bonding of the insert in the molded rubber article.
The Van Dusen U.S. Pat. No. 1,766,471 discloses a laminated material comprising a metal sheet having hard vulcanized cellular rubber mats on opposite slides thereof that may be used in lieu of wood in structural applications with an additional metal sheet overlying one or both of the rubber mats. U.S. Pat. No. 3,472,728 to Hitch and U.S. Pat. No. 3,834,962 to Strumbos also disclose reinforced foam structural members.